Search

ObjectiveTo investigate the association between deletion of key virulence genes and pathogenicity and serotype of 81 strains of Listeria monocytogenes(L.monocytogens) isolates in Chaoyang district of Beijing from 2016-2018.MethodsSerotyping was performed on 81 strains of L. monocytogenes by polymerase chain reaction (PCR) and serum agglutination assay, and 11 virulence genes (inlA, inlC, inlJ, plcB, prfA, mpl, iap, hly, actA, inlB, plcA) were detected by PCR. The susceptibility of these strains to 9 antibiotics were tested by broth dilution. Based on the epidemiological survey data, the relationship between the deletion of key virulence genes, pathogenicity and serotype of L. monocytogenes was studied.ResultsThe 81 strains of L. monocytogenes were classified into 4 serotypes: 1/2a serotype 50.62% (41/81), 1/2b serotype 29.63% (24/81), 1/2c serotype 11.11% (9/81) and 4b serotype 8.64% (7/81). The predominant serotype of food isolates and patient isolates were 1/2a. The positive rates of virulence genes inlA, inlC, inlJ, plcB, prfA and mpl were 100%. The positive rates of iap, hly, actA, inlB and plcA were 98.77%, 98.77%, 97.53%, 80.25% and 38.27% respectively. The proportions of the 81 strains of L. monocytogenes carrying 7, 8, 9, 10 and 11 virulence genes were 1.23% (1/81), 2.47% (2/81), 7.41% (6/81), 59.26% (48/81) and 29.63% (24/81). The positive rate of hly in genotype 1/2c was lower than that in other serotypes, and plcA was only 100% carried in genotype 1/2b and 4b. 70.37% (57/81) isolates lacked 11 virulence genes and 1/2a (41/57, 71.93%) was the main serotype. Only inlB was not detected in 1/2b (6/24, 25.00%) and 4b (1/7, 14.29%) serotype. There was no significant difference in the distribution of gender, age, pregnancy related or not, and the source of strains in 16 virulence gene deletion strains isolated from patients (P>0.05). The resistant rates of 81 strains of L. monocytogenes to penicillin, erythromycin and ampicillin were 4.94%. MIC to chloramphenicol of 57 strains was as high as 16 μg/mL and MIC to the other antibiotics was low. There were three drug-resistant strains in the virulence gene deletion strains, and one inlB deletion strain was resistant to penicillin, erythromycin and ampicillin. Another inlB deletion strain was resistant to penicillin. The plcA deletion strain was resistant to erythromycin.ConclusionThe dominant serotypes of L. monocytogenes isolated from food and patients in Chaoyang district of Beijing was 1/2a. There were some virulence gene deletion strains. Deletion of some virulence genes had limited effect on pathogenicity of L. monocytogenes strains. The drug resistance rate of L. monocytogenes isolated from food and clinic was low, but surveillance and control of virulence genes and drug resistance of L. monocytogenes should be strengthened.

Flexible zinc‐air batteries (FZABs) have emerged as a promising alternative to lithium‐ion batteries in flexible electronic devices due to the advantages of excellent mechanical properties, high energy density, and notable safety. However, the unclear causes of performance degradation and failure mechanisms of FZABs significantly impede their commercialization. Therefore, extensive research is needed to fully reveal the factors and mechanisms responsible for the performance decline of FZABs. In this review, the failure mechanisms of FZABs' key components, including the Zn anode, solid electrolyte, catalyst air cathode, and electrolyte/electrode interface are analyzed and discussed. To promote further research and development of FZABs, a series of challenges and corresponding strategies are summarized and analyzed. Finally, the future development of FZABs is envisioned. This paper aims to comprehensively elucidate the failure mechanisms of FZABs, guide the development of high‐performance FZABs, and thus promote their commercialization. [ABSTRACT FROM AUTHOR]

Industrial land is essential for supply-side structural reforms, particularly in the Chengdu–Chongqing area, Western China's most densely populated and industrially robust region. This area, a pivotal hub linking Southwest China with South Asia and Southeast Asia, is critical for the national strategic layout and regional economic restructuring. Despite its substantial industrial foundation as an old industrial base, internal developmental stagnation has led to an irrational industrial land use structure. This paper analyzed land transaction data from the China Land Market Network (2010–2021) using methods such as kernel density estimation, the standard deviation ellipse method, and Global Moran's I index. The analysis focuses on the spatiotemporal evolution of industrial land marketization and its driving factors in 44 cities within the Chengdu–Chongqing economic circle. The findings aim to enhance the strategic implementation of national policies and regional economic optimization, suggesting intensified development efforts in key cities and promoting integrated growth in potential areas like Suining and Ziyang to foster a conducive environment for high-quality regional development. [ABSTRACT FROM AUTHOR]

The development of advanced unmanned robots is of great significance to promote scientific progress and innovation, expand application fields, and improve efficiency and safety. Complex perception, motion, and navigation systems consisting of numerous sensors and powerful processors enable robots to monitor various sophisticated environments. However, the available commercial batteries cannot satisfy the long endurance and safety requirements of robots. Herein, we propose the application of metal–air batteries to power robot devices considering their advantages of higher energy density, lower cost, and better safety compared to lithium-ion batteries. Furthermore, the technological development of metal–air batteries in terms of specific energy, cycle life, fast charging, environmental adaptability and flexibility has increased the possibility of their application in next-generation unmanned devices. Accordingly, we present an outlook on the application of metal–air batteries in all fields of robotics, including land, air and sea, embodying the temporal and spatial infinities of these batteries. It is expected that the application of metal–air batteries will promote the advancement of the robot industry. [ABSTRACT FROM AUTHOR]

Flexible zinc‐air batteries have received widespread attention due to their high specific energy and eco‐friendly environment. However, the water in the hydrogel is easily lost to the external environment because of the semi‐open structure zinc‐air batteries, leading to performance degradation of the batteries. Here a saline gel of NaCl‐KOH‐PAA (sodium chloride‐potassium hydroxide‐polyacrylic acid) without soaking in the alkaline solution before use is designed, refining the grid structure of the hydrogel and reducing water loss through NaCl doping. Meanwhile, the gel exhibits no significant decrease in ion conductivity before and after NaCl doping and can maintain stability of around 170 and 150 mS cm−1 at room temperature and −20 °C, respectively. The results demonstrate that the lifetime of flexible zinc‐air batteries with NaCl‐doped hydrogel can be extended by nearly 50%. The NaCl doping gel also displays superior flexibility under extreme physical deformation conditions. Moreover, the phenomenon of hydrogel delamination with NaCl doping is observed and the mechanism of gel water retention is uncovered. These findings will pave the way for developing flexible zinc‐air battery. [ABSTRACT FROM AUTHOR]

Metastable structures are promising candidates for efficient catalysis owing to abundant active electronic states, strong electronic coupling with reactants, and energetic preference. Exerting the value of metastable structures while evading the difficulty in direct synthesis remains challenging. Herein, it is reported that light irradiation enables the generation and maintenance of the metastable state over copper single atoms for efficient carbon dioxide reduction. Under irradiation with light, photogenerated electrons transit to Cu‐3d orbits and initiate d‐orbital rearrangement. The initial symmetric Cu1─O4 coordination converts to the metastable asymmetric structure of Cu1─O2+1, and is reversibly restored after removing the light. The photoinduced metastable intermediate of Cu1─O2+1 promotes the Cu single‐atom catalyst to deliver an ethylene yield rate of 60.4 µmol gcat.−1 h−1. Mechanistic studies reveal that Cu1─O2+1 possesses stronger adsorption capability for reactants and intermediates. The reaction energy barrier over Cu1─O2+1 also shows an obvious decline compared to that over Cu1─O4. [ABSTRACT FROM AUTHOR]

Herein, a fluoropolymer bifunctional solid membrane interface (SMI) for an aqueous Al–air battery is proposed, which inhibits anodic self-corrosion, while concurrently reducing the accumulation of undesirable by-products. A battery using the SMI exhibits a remarkable anticorrosion efficiency of 81.31% and achieves an astonishing battery lifetime improvement rate of 184.37% under the condition of 5 min intermittent discharge. [ABSTRACT FROM AUTHOR]